KIRKUK, Iraq - A series of apparently coordinated bombings across Iraq on the eve of a Muslim festival marking the Islamic new year killed 15 people and wounded dozens of others on Wednesday, officials said.

The blasts -- six car bombs and a roadside bomb -- struck in Baghdad and four other cities, the security and medical officials said, and will likely raise tensions in a country that only recently emerged from a brutal sectarian war.

No group immediately claimed responsibility for the spate of violence, but Al-Qaeda's front group in Iraq frequently carries out coordinated bombings and attempts spectacular mass-casualty attacks in a bid to destabilise the government through fomenting bloodshed.

Wednesday's deadliest blasts struck in Kirkuk, a disputed ethnically-mixed oil-rich province in north Iraq that is frequently targeted by militants seeking to sow communal violence, where at least nine people were killed and 39 wounded.

Two car bombs and a roadside bomb in Kirkuk's eponymous capital city killed five people and wounded 34 others, while another explosives-packed vehicle targeting an Iraqi army patrol in the town of Hawijah, also in Kirkuk province, left four dead and five others wounded, according to officials.

"My child was killed! His friends were killed!" Shukriyah Rauf screamed in Kurdish at the site of the worst of the Kirkuk city attacks, where a car bomb and a roadside bomb in a majority-Kurdish neighbourhood killed five.

"There is no security here, our homes were destroyed!"

The attack that killed Rauf's child struck near offices of the Kurdistan Democratic Party, Iraq's most powerful Kurdish political party which is led by Massud Barzani, president of the autonomous Kurdistan region.

The other attack in the city wounded seven municipal street cleaners.

"The car bomb targeted our friends -- they are not police, soldiers or politicians," wailed Jassim al-Obeidi. "They just wanted to make a little money."

Kirkuk province lies at the centre of a tract of disputed territory that is claimed by both the central government and the Kurdish region, and the unresolved row is cited by diplomats and officials as the biggest long-term threat to Iraq's stability.

South of Baghdad near the city of Hilla, meanwhile, a car bomb in a parking lot near a crowded marketplace killed five people and wounded 35 others, police and medics said.

Another car bomb in Baghdad's Firdos Square, the site famous for Iraqis pulling down a statue of Saddam Hussein shortly after the 2003 US-led invasion, killed one person and wounded six others.

A sixth car bomb in the town of Baladruz, in restive Diyala province, wounded six.

The violence comes a day before Muharram, which marks the Islamic new year on the lunar calendar.

Violence in Iraq is dramatically lower than its peak in 2006 and 2007 when the country was in the throes of a brutal sectarian war, but Sunni militants still carry out attacks, typically in a bid to target the Shiite-led government, its institutions and supporters.